Carburetor



Dec. 29 1925- C. J. GUSTAFSON CARBURETOR I Filedr'Feb. 11. 1,918A 2 SheetS-Sheet-l Deco 2 sheets-sheet 2 c. J. GUSTAFSON CARBURETOR Filed Feb. 11. 1918 Patented Dec. 29, 1925.

Y UNITED STATES CHARLES J'. GUSTAFSON, OF CHICAGO, ILLINOIS,

DEVICES COMPANY, OF CHICAGO, ILLINOIS,

ASSIGNOR T0 STROMBEBG MOTOR A CORPORATION OF ILLINOIS.

CABBUBETOR.

Application liled Februaryv11,1918. Serial No. 216,430.

To all lwhom it 17mg/ concern.'

Be it known that I, CHARLES J. GUSTAF- sON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement 4in Carburetors, of which the following' is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification. v

My invention relates'to carburetors.

In supplying mixture to an internal combustion engine, only the quantity demanded by the engine for developing the necessary power but to provide the proper quality of mixture to correspond to the conditions of the engine, such as starting, idling, accelerating and running at various speeds.

It is one of the fundamental objects of the present invention to provide means for exer cising as wide a range of control over the mixture proportion for all engine conditions as possible. This range of control I effect by a novel combination of air vents or air bleed ports which open into the fuel nozzle.

One supply of air which is vented into the g `fuel stream is controlled by the position of the throttle, and this air supply is preferably arranged so as to reduce the proportion of fuel in the mixture, particularly at cer-l tain engine speeds. Another supply of air vented 1nto the'fuel stream is dependent on the suction effective at the fuelnozzle, and this air vent is so arranged that a temporary accelerating charge of fuel is obtained with the increases of suction at the nozzle. `quantity of fuel discharged from the nozzle is therefore subject to the suction existing atthe nozzle. The two air vents alsg operate, of course, to compensate for the natural tendency to produce an excessively rich mixture at the higher engine speeds.

In order to expla-into those skilled in the art the construction and use of my invention,

I shall now describe an embodiment of thel same in detail, in connection with the accompanying drawings which form a part of this speciication.

Figure 1 is a top plan view vof a carburetor embodying my invention;

Figure 2 is a vertical longitudinal section of the same;

l Figure 3 is a cross section taken on the line it is essential to provide, not

The

to throttle position and- 3-.3 of Figure 1, looking in the direction of the arrows;

Figure bis a fragmentary sectional View taken on the line 4-4 ofFigure 1 looking in the direction of the arrows;

Figure 5 is a front elevational view taken on the right of Figure 1; I

Figure 6 is a section taken on the line 6-6 of Figure 1, looking in the direction of the arrows `and Figure 7 is a fragmentary sectional view.

Fig.l 8 isa reduced fragmentary sectional view.

The carburetor illustrated in the drawings comprises a horizontal barrel portion 1, which is provided flange 3 for suitablel attachment to the manifold of the engine. A' constant level chamber 4, providedwith suitable float valve mechanism (not shown), is /formed as an integral part of the main barrel or casing 1. The main barrel or casing 1 is provided with an enlarged inlet portion 5 which is connected to an intake elbow 6. The open end of the intake 5 is embraced bythe elbow 6 which is provided with a split lug 7 and a bolt 8' for ripping the periphery of the intake 5 so that the elbow 6 may be adjusted in any desired osition. The intake elbow 6 has a suitab e intake opening 9 and is provided with a butterfly valve 10, controlling the entry of air to the barrel of the carburetor.

The main barrel member 1 contains the main venturi 11 whichfits within the side walls of the barrel. A secondary, -or smaller, Venturi tube 12 is mounted in the top of the post 13 and has its inner end extending beyond the most restricted portion of the main venturi 11. The upper end of the post 13 has an enlarged head which is bored out to receive the smaller venturi 12, holding it in accurate alignment with the larger venturi 11.

The post 13 is hollow and has an extension below the walls of. the enlarged intake 5. This extension 15 is also hollow and has its lower end threaded to receive a correspondingly threaded head 16 which divides the interior into an accelerating well 17 above the head 16 and a primary well 18 below the head 16. 18 is closed by means of the plug 19.'

The head 16 has a. hollow sleeve 20. This with an outlet 2 having a,

` The lower end of the primary well sleeve 20 has a shoulder 21 whichv engages .the restriction formed in theA uper end of Separate the bore ofthe post 13-15.

' sleeve 22 spaced from the sleeve 2O sufficient nozzle, thereby forming an atomizing chamber about said nozzle.

lt will be noted that the tip of the nozzle 24 extends above the door of the atomizing chamber to secure an effective atomization of the fuel by the air entering the passageway 63.

A plurality of smalll passages 26 provide communication between the annular space 23 and the atomizing chamber 25. A number of small openings 28 are formed along the side of the sleeve 20, providing communication between the accelerating well 17 and the annular space23.

The accelerating well 17 communicates with the primary well 18 through a plurality of openings 29 formed through the head 16.

rlhe atomizing chamber 25 communicates by way of a threaded nipple 30 with the opening or nozzle 31 formed in the small venturi 12.` This nozzle opening is slightly beyond the most restricted portion of the venturi 12. lt will be noted that the threaded nipple is threaded in the upper end of the bore of the post 13, and projects Into a recess in the venturi 12, thereby securely l holding the parts together. n

.The primary well communicates by way4 of a passage 32 through a restriction formed between the valve 33 and the corresponding seat 34 with the space 35, which forms a part of the oat chamber and serves to seal the valve opening 34 against the entry of air or leakage of fuel at this point.

The valve 83 is provided with a stem 36 threaded at its upper end through a wall 37 on the upper side of the space 35. A lrnurled head 56 permits adjustment of the valve 33.

lt is to be noted that the positioning of the valve 38 is such that a leakage of air past the threaded part of the 36 can not vary the proportions of the mixture as this valve is arranged upon the iloat chamber side of the restriction.

v l provide a throttle valve 4l between the outlet 2 and the carbureting chamber 40, rlhis valve is mounted upon a rocker shaft 42 and operated by suitable lever (not shown). An .idling1 nozzle 43 is placed at the left' of the throttle 41, this nozzlev being supplied with fuel by way of a passagev 44 lying within the rib 45 formed Ln 1 1 upon the gutside or the barrel 1 anc supplied with air through the opening 95 which extends through the side wall of the venturi ll and the wall of the barrel. l. l suitable acarrea needle valve having the adjusting head 46 controls the flow of air from the interior of the carburetor to the idling jet 43.

rllhe face of the idling jet 43 is depressed slightly below the surface of the bore of the chamber 1 to give a small passageway for air when the throttle valve 41 is otherwise closed and to prevent the opening and closing of the throttle' valve 41 from affecting the opening of the liet too sharply.

The passageway 44 .which supplies fuel to the idling nozzle 43 communicates by way of a diagonal passage 48 with the annular space 49 formed by a groove in the sides of the head50, which is threaded into the open bore which is drilled down through the boss 51. lrEhe head 50 has a hollow stem 52 extending down and engaging a shoulder 53 at the lower end of the bore. rlhe passageway 54 in the stem'52 communicates by way of the radial openings 55 with the annular space 49. At its lower end the passageway 54 communicates by way of the tube 56 with the fuel passageway 32.

rlhe tube 56 has a restriction 57 controlling the maximum flow of fuel to the idling jet.

An annular space 60 is formed between the stem 52 and the side walls of the bore, this annular space communicating at its upper end with an opening 61 to the interior of the easing 1, as indicated at the reference character 62 in Figure 2.

At its lower end, the annular space 60 communicates with the horizontal passageway 63 which leadsinto chamber 25.

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The opening 6l permits air to enter and to s pass into the atomizing chamber 25 for the purpose of air bleeding the jet 31. This opening 61 is controlled by a valve 65 which is connected by the stem 66 to a short operating lever 67, mounted on the roclring shaft 42 that controls the throttle 4l. The

upper end of the lever 67 is bifurcated as is shown in Figure l to embrace the valve rod 66. The bifurcated ends 68 are rounded and engage a threaded head 69 on the end of the valve rod 66, this head being held in place by means of the lock-nut 70. A spring lies between the valve member 65 and the guiding sleeve 7l, which lits into the bore 72 (see ldigure 6) in which the vlave 65 is i guided. This sleeve 7l embraces the stem 66 and forms a guide therefor. The relation between lthe throttle valve 41 and the bleeder valve 65 is such that when the throttle is in closed position, the bleeder valve 65 is in its maximum open position. lhus, when the throttle is substantially closed, the air dows in through the opening 61 displacing a certain amount of the fuel and reducing the proportions of fuel to air, forming the mixture.

A certain amount @fair may be admitted t0 the atomizing chamber at all lms. by.

ist

having a small normally open orifice as shown at 85 1n Figure 7 which admits air at all times, chiefly for the purpose of atomiz-L ing the fuel in the chamber 25.

The accelerating well 17 communicates with atmosphere outside the carburetor by way'of the horizontal passageway 7 5 and the vertical passageway 76 and the graduated or restricted passageway plug 78 at the topl of the passageway (See Figure 6.) 4 y The operation of the device is as follows:

The level of the gasoline in the float chamber 4 normally stands slightly below the opening or nozzle 31 in the secondary venturi l2. as indicated by the'dotted line A.-B. Then it is desired -to start the enc-ngine, the butterfly valve 10 in the air inlet is closed by a manual adjustment controlled preferably from the'dashboard of the vehicle. The engine is then turned over with partial open throttle creating a suction in the manifold and interior of the carburetor, thereby drawing fuel out at the nozzle 31 and at the idling nozzle 43. It is to be noticed that when the parts are at rest the passageivays heretofore described are allilled with gasoline to the level of the line A-B. Thus, the passageways 63 and 75 contain fuel which is available for starting purposes. As the airinlet is very greatly restricted and as the fuel discharged is in great excess of i the' air entering at that time', the Volatile constituents of the fuel form with the enter- `ng air a mixture sufficiently rich to start the engine.`

When the engine is idling, the throttle valve 4l is closed (or substantially closed) and fuel is fed at the idling nozzle 43, the velocity of the 'air being great enough around the lip of the Vthrottle to atomize the fuel thoroughly.

It will be noticed that the air which is drawn past the idling nozzle 43 first passes through the main body of the carburetor, thus passing the main nozzle and the idling nozzle in series, The same is true of the air'bleed for the idling nozzle, this air be- I ing taken from the inside of the barrel.

As soon as the throttle 41 is opened fur- `ther to increase the speed of the engine, a

greater quantity of fuel is drawn at the i nozzle 3l and a less quantity at the nozzle 43,

relatively. Thus. the function of supplying fuel to forni the mixture passes gradually from the idling nozzle 4S to the main nozzle Ill. p

The arrangement of the double venturi secures a greater suction' upon the nozzle 31, thus ensuring the proper discharge even at a relatively low rate of entry of the air.

As the gasoline which is at present supplied on the vmarket consists in a major propoi-tion of hydrocarbons which are not volafile at atmospheric pressure and tempera-V ture, the

I7 formedin the fuel iuust be sprayed rather (than .'aporized and carried into the manifold in the sprayed or atomized form. So long as tliethrottle is ifi such position as to restrict the flow of air` materially', the suction within the manifold will be substantially' high Under the drop of pressure which prevail.Q at that point, the less volatile hydrocarbons are Volatilized and forma better and more workable mixture. To secure the same explosive etfe'ct, the mixture, when the fuel is properly vaporized, maybe lower in proportion of fuel to air than when the fuel is drawn in substantially at atmospheric pressure in the Iform of a spray or mist.

For this reason, the air bleeder for the main jet is given a maximum opening when the throttle is closed as this condition of the throttle corresponds with high suction in the "manifold of the throttle, 41. During conditions of i running, air enters the restricted orifice 'i' 7 in the plug 78, passes down through the passageways 7 6--75, displacing some of thev gasoline. to the point that the level of the fuel drops below the uppermost-opening 28 in the side walls 'of the sleeve 2O air is admitted at this opening, passes into the annular'space 23 between the sleeves 2() and 22, and is drawn up through the small openings 26 around nozzle 24. The action of thel air drawn in at this point vis to atomize the fuel which is drawn oif at the top of the nozzle 124, breaking the same Aup into a line spray tering at that point passes up as bubbles and the fuel is held between bubbles and appears as slugs as it is discharged from the nozzle 24.

As the suction inthe nozzle 3l increases more fuel will be drawn out of the accelerating well, this fuel passing down by way of the passages 29 in the head 16 and up through the sleeve 22 and the nozzle 24. lf further openings 2S are uncovered ,the amountI of air passing up through the annular space 23 and the passageways 26 is increased until the suction is satisfied and conditions reach an equilibrium.

The compensating air bleed, controlled by the valve 65, extends over arange of positions .of the throttle 41 from closed to substantially1 one-third open. Thereafter the compensating air bleed is closed by the When the suction has increased lll() valve G5 and the air bleed from the accelerating well is depended upon solely.

I do not intend to be limited to the precise details of construction shown and described.

' I elaim:-

1. In a carburetor having an air inlet, a Y'nixture outlet and .a throttle controlling said outlet. a main nozzle, an accelerating well, a connectionv from said accelerating well to said main nozzle, venting means for admitting air to the upper part of said acfelerating well, air venting means for said I main nozzle, and means for decreasing the venting of said main nozzle as the throttle sage receiving fuel therefrom, two passages omni-nicating with said {i1-st passage, a main nozzle in one of said two passages, the other of said two passages being enlarged intermediate its length, a hollow plug in said enlarged passageway, an idling port receiving fuel from the inner bore of said plug, an annular passage between said plug and the enlarged portion of said passage, said annular passage lbeing closed at both ends by said plug, and lateral passages formingr with said annular passage an airbleeding channel for said main nozzle.

Inwitness whereof Lhereunto subscribe my name this 8th day 'of February, A. D. 1918.

CHARLES J. GUsTArsoN. 

